Cut-out relay



N. R. HAAS.

CUT-OUT RELAY.

APPLICATION FILED FEB. 4, I918.

1,327,951. Patented Jan. 13,- 1920.

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1 UNITED STATES rac sm cr mes.

NELSON R. HAAS, 0F DAYTON, OHIO, ASSIGNOR TO THE DAYTON EhTGINEERINGLABORATORIES COMPANY, A CORPORATION OF OHIO.

CUT-OUT RELAY.

Specification of Letters Patent.

Patented Jan. 13, 1920.

To all whom it may concern:

Be it known that I, NELSON R. HAAS, a

citizen of the United States of America, residingat Dayton, county ofMontgomery, and State of Ohio, have invented certain new and usefulImprovements in Cut-Out Relays, of which the following is a full, clear,and exact description.

This invention relates to improvements in cut-out relays, and moreparticularly to that type used in connection with automobile starting,lighting and ignition systems.

It is an object of the present invention to provide'improved meanswhereby the electrical connection between certain cooperating contactelements forming a part'of the apparatus is rendered more effective.

Further objects and advantages of the present invention will be apparentin the following description, reference being had to the accompanyingdrawings, wherein a preferred form of one embodiment of the presentinvention is clearly set-forth.

In the drawings Figure 1 is a diagrammatic view of the relay and itselectrical connections.

Figs. 2, 3 and 4 are side views of the contact carrying end of thecut-out relay, which show the movable contact element in variouspositions. Some of the parts of these views have been broken away forthe sake of clearness.

Figs. 5 and 6 are detail views of the re lay of the movablecontactelement.

Referring to the drawings, there is shown a relay having a frame 20which carries a core21. This core supports a fine winding 22 and a heavywinding 23,-the functions of which are fully described hereinafter. Astationary contact element 24 is rigidly secured to the relay in any,suitable manner. An armature 25, fulcrumed on theirame at the point 26,supports a strip 27, and low resistance movable contact 28, and highresistance contact carrying element 30, said strip 27 and contacts 28and 30 being secured thereon by means of screws 42. The low resistancecontact 28 includes a plurality of strips or laminations 29, and thecarrying element: 30 may be constructed of spring steel or other similarmaterial and has a resistance element 30 secured at its outer extremity,

A headed pin 25 extends through slot 30 in contact .30 and slot 28 inntact 28 and is mounted upon armature 25. The purpose of this pin 25will be described later.

By referring to Figs. 2, 3 and 4, it can be clearly seen that the highresistance element 30 projects beyond the extremities or contact face ofthe strips or 'laminatio-ns 29. This permits the high resistance element30 to come into contact with the stationary contact element 24, beforeany of the strips or laminations 29, of the contact element 28, as isclearly shown in Fig. 2.

A spring element 31 is secured to the one end of the strip 27, and tendsto pull or 7 force the armature 25 away from the core 21.

By referring 'to Fig. 1, the system is' shown including a generator 32,having field windings 33, and connected to the storage battery 34, bymeans of the relay and line connection 35.

Now, when the generator starts to generate, current will first start tobuild up in the field 33. As soon as this building up eflect has reacheda determined point, current will flow from the brush 36, through wire37, to the point 38, thence through the fine winding 22 of the relay, tothe point 39, back to the generator via the wire 35.

When the core 21 has become energized suiiiciently to attract thearmature 25, the tension of the spring 31 is overcome, causing themovable contactelements 28 and 30 to be brought into engagement with thestationary contact element 24 in the following manner. v

First the high resistance element 30 carried by the contact element 30will be brought into engagement with the stationary contact element 24(see Fig. .2).

Further movement of the movable contact will bring the strips orlaminations 29 into engagement with the stationary contact (see Fig. 3),at which time current will flow from the generator 32, through brush 36,wire 37, to the point 38, and thence through the heavy winding 23,across the stationary contact 24, movable contact 28, wire 40 to thebattery 34, and back to the opposite side of the generator via the wire35.

As the current in the generator is being built up to maximum, thearmature 25 will be attracted by the relay magnet with a c rrespondinglyincreas ng force. It is highly desirable that the pressure betweencontact element 24:, 28 and 30 be increased as the charging currentincreases in order to increase the efiectiveness of the electricalcommotion-made by said contact elements, The increased armatureattraction 'is utilized to accomplish this result in the followingniannerz During the movements of the armature 25, as shown by Figs. 2and 8, any bending of the contact elements 28 and 30 will take placeabout the ends thereof held fixed by screws L2. But when the armature isstrongly attracted and broughtinto touching relation with the core2l,the head o1 pin 25 will so cooperate with elements 28-and 30 that allbending thereof will take place between said pin 25 and the free ends ofsaid elements 28 and 80. This condition is clearly shown in l. The pin25 automatically produces a shortening in the erl'ective length of themovable contact elements 28 and 30 with the result that the pressureexerted. upon the stationary contact 24 is greatly increased beyond.that which would occur, were the bending of said movablev elements to bepermitted to take place about the lined ends without any obstructioncoming into engagement with said movable elements at some pointintermediate their lined and free ends, 'By this means the pressurebetween the movable and stationary contact elements is increased inproportion to the amount of current to be carried,

During the movement of the armature 25 there is a change in the bendingrateoii contacts 28 and 39.: During the initial. movement of thearmature through the stages illustrated by Fig. 2 and 8, the contactswill, bend at a substantially uniform rate about their ends fixed byscrews 42. But during the final movement oi" armature 25, beginning withthe instant-f when the head of pin 25 comes into'engagement withcontacts 28 and 30 until the linal stage is reached as illustrated inFig. 4:, the bending of said contacts with relation to the are maturetakes place at an increased rate.'

The term bending rate will be understood to mean the relation betweenthe deflection or the laminated contact 28- perunit of free length ofsaid contact to the movement of the armature. The free length oi thelaminated contact 28 will be understood to mean the distance the freeend of said con tact to the point about which the contact bends. lltwill be understood from the fore going description there is an abruptchange from one portion about which the laminated contact bends to an.intermediate portion,

hence it follows there must be an abrupt change in the bending rate.This abrupt change in the bendlng rate s necessary for successfuloperation of the device to which the present invention relates, the

earner Inbnt of the armature when the bending rate a is increased in themanner describedjthe contact 28 is less flexible than before, hence theattraction or" the magnet upon the armature is more eiiective to producean increased pressure between contacts 28 and 29. Therefore it will beseen that when the current t be carried is the greatest, the magnet willexercise the greatest attractive eli'ect upon the armature to producethe greatest possible-amount oi? contacting pressure between contacts 28and 29 to carry this large amount of current;

It is desirable to have the contacts 28 remain in the more flexiblestate as long as possible in order that suthcient scraping actionreferred to may take place and tend to clean the contact 24b Then it isdesirable to bring the contacts 28 and 29 together under pressure assoon as possible after this scraping action has taken place. To bringvabout these results it is necessary in devices of this character topermit the initial action of the laminated contact to take place withundiminished efiect up to a certain point and then to suddenly changethe bending action in order that the necessary pressure between thecontacts may be promptly applied.

llt will of course be understood that when the charging rate of thebattery decreases, so that the core 21 is unable to hold the armature 25in attracted position, the above described action of the relay reverses,that is, the strips or laminaticns 29 will first break engagement withthe contact element 24%, after which the high resistance element 30 willbreak away from the stationary contact, and owing to. this decreasedhow, on account of the relatively high resistance of the element 30 thesparking at this point will substantially be eliminated.

By reason of the head of pin 2'5 engaging contact elements 28 and 30 inthe man- .ner described, thus requiring more force to produce the samedeflection of the free ends of said elements than in the case wherethe Ybending of said elements is unobstructed, the

rec

operate with spring 31 to produce a more quick separation of saidcontact from con tact 24, thereby eliminating sparking and pitting to alarge extent.

In order to compensate for different vari= ation in the charging rate ofthe generator, the movable contact element 28 is provided with elongatedslots 41, which are adapted to receive a screw 42 which clamps themovaple contact element securely to the strip 2 made by loosening saidscrews 42, and after proper adjustment has been obtained, said screwsmay again be tightened to clamp the movable element in the desiredposition.

While the form of mechanism herein shown and described constitutes apreferred form of embodiment of the invention, it is to be understoodthat other forms might be adopted all coming within the scope of theclaims which follow.

What I claim is as follows:

1. In a device of the kind described, the

combination with cooperating contacts for completing an electriccircuit, one of the contact elements being flexible; of provisionsnormally maintaining the contacts apart; electro-magnetic means causingthe contacts to come together under pressure; and a member actuated bythe electro-magnetic means, cooperating with the flexible,

contact for causing an abrupt change in the bending operation of theflexible contact during the operation of electro-magnetic means:

2. In a device of the kind described, the combination with cooperatingcontacts for completing an electric circuit, one of the contacts beingflexible; of provisions normally maintaining the contacts apart;electro-magnetic means causing the contacts to come together underpressure thereby causing the flexible contact to bend about a certainportion thereof during the initial bending operation; and a memberactuated by the electro-magnetic means, cooperating with the flexiblecontact for abruptly causingbending to take place about a differentportion thereof during the final bending operation.

3. In a device of the kind described the combination with coop'eratingcontacts for completing an electric circuit, one of the contacts beingflexible; of provisions normally maintaining the contacts apart;electro-magnetic means causing the contacts to some together underpressure, whereby the flexible contact will bend at a certain rateduring the initial operation of the electro-magnetic means; and a memberactuated by the electro-magnetic means and cooperating during the finaloperation of the electro-magnetic means with the flexible contact toproduce an abruptly increased bending rate of the flexible contact withrelation to the operation of the electro-magnetic means,

Any variation or adjustment can be 4. In a device of the kind described,the combination with cooperating contacts in an electric circuit, one ofwhich is flexible and means normally holding the contacts apart; of astationary support for one of the contacts; amovably mounted armaturesupporting the other contact; an electro-magnet cooperating with thearmature said magnet when energized causing the'contacts to be.

brought together whereby the flexible contact is bent at a certain rateduring the initial movement of the armature; and a member actuated bythe armature during the final movement of the same, and (:0- operatinguith the flexible contact to produce an abruptly increased bending rateof the flexible contact with relation to the movement of the armature.

5. In a device of the kind described, the combination with cooperatingcontacts in an electric circuit, one of which is flexible and meansnormally holding the contacts apart; of a movably mounted armaturecarrying the flexible contact; an electro-magnet cooperating with thearmature and causing the contacts to be brought together whereby theflexible contact is bent at a certain rate duringthe initial movement ofthe armature; and a. member mounted on the armature, and having aportion thereof adapted tocooperate during the final movement ofthearmature with the flexible contact to produce an abruptly increasedbending rate of ,the flexible contact with relation to the movement: ofthe armature.

6. In a device of the kind described, the combination with cooperatingcontacts in an electric circuit, one of which is flexible and a springfor normally holding the contacts apart; of an armature upon which ismounted the flexible contact by securing the same at one end to thearmature; an electromagnet cooperating with the armature causing thefree end of the flexible contact to touch the other contact withpressure where by the flexible contact is bent at a certain rate duringthe initial movement of the armature; and a headed pin mounted on thearmature having the head portion thereof adapted, during the-finalmovement of the armature, to cooperate with the flexible contact toproduce an abruptly increased bending rate of the flexible contact withrelation to the movement of the' armature.

7. In a device ofthe kind described, the combination with cooperatingcontacts in an electric circuit, one of which is flexible, and a springfor normally holding the contacts apart; of a pivotally mountedarmature; and an electro-magnet cooperating with the armature; and meansactuated by said armature to effect the engagement of said contacts andto cause initially the bending of v the flexible contact about a certainpoint thereof, then abruptly causing. the bending lee of said flexiblecontact about a difierent por-- tact with said rigid contactj and meansoperated by said armature for causing the bending of said flexiblecontact to take place abruptlyv about an intermediate portion of 15 saidflexible Contact,

In testimony Whereoi a'ffix my signature.

NELSON n. ans.

Witnesses 'WARREN SCHMIEDING, invm A.- GIEENWALD.

